Storm Drainage
Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
Showing changes from Rev 5
to Rev 6
in Storm Drainage.
---
title: Storm Drainage
…197 unchanged lines
### RCP is available in five classes (Class I through Class V) reflecting increasing strength designations under the three-edge bearing test. {note}
+### The class for each reach shall be as indicated on the pipe schedule and shall be chosen by the civil engineer based on cover depth, live load, trench width, and bedding class.
+
```datasheet
label: RCP Strength Class
…8 unchanged lines
```
−### The class for each reach shall be as indicated on the pipe schedule and shall be chosen by the civil engineer based on cover depth, live load, trench width, and bedding class.
−
### Class III RCP is the most commonly specified class for typical commercial site storm drainage with cover depths of approximately 3 to 12 feet and HS-20 live loading, while Class IV and Class V are used where cover is shallow, where trench widths exceed the standard installation envelope, or where unusually heavy live loading is anticipated; the class designation reflects the structural design assumption of the civil engineer. {note}
…12 unchanged lines
### High-density polyethylene corrugated dual-wall pipe conforming to AASHTO M294 Type S (12 in. and larger) or AASHTO M252 (3 in. through 10 in.), and to ASTM F2306 for the 12-in. through 60-in. size range, is widely used for site storm drainage in private development where cover depth, live load, and pipe size are within the range supported by the AASHTO design specifications. {note}
+### The minimum pipe stiffness (PS) of HDPE corrugated dual-wall pipe shall be specified, increased above the AASHTO minimum where cover depth, live load, or pipe size requires higher stiffness.
+
```datasheet
label: HDPE Pipe Stiffness (PS) Minimum
…28 unchanged lines
- ASTM F949 (4-in. through 36-in.), corrugated/profile-wall PVC pipe with smooth interior
+### The PVC pipe type and governing ASTM standard for storm drainage shall be specified for each pipe size range indicated on the drawings.
+
```datasheet
label: PVC Pipe Type for Storm Drainage
…135 unchanged lines
- **Trench drain:** A linear surface drain used to collect sheet flow across a paved area, typically at vehicular entrances, loading docks, or wide pedestrian plazas.
+### The inlet type shall be specified for each location based on grade condition, drainage configuration, and surface type.
+
```datasheet
label: Inlet Type by Location
…64 unchanged lines
# Castings {toc}
−## General {toc}
+## All inlet frames, manhole frames, manhole covers, inlet grates, and area drain grates ("castings") shall be gray iron conforming to ASTM A48 or ductile iron conforming to ASTM A536, listed in accordance with AASHTO M306.
−### All inlet frames, manhole frames, manhole covers, inlet grates, and area drain grates ("castings") shall be gray iron conforming to ASTM A48 or ductile iron conforming to ASTM A536, listed in accordance with AASHTO M306.
+## Castings shall be free of visible defects (cracks, cold shuts, blowholes, inclusions), shall be machined at mating surfaces where required to seat the cover or grate flat in the frame without rocking, and shall bear the foundry identification and the AASHTO M306 mark.
−### Castings shall be free of visible defects (cracks, cold shuts, blowholes, inclusions), shall be machined at mating surfaces where required to seat the cover or grate flat in the frame without rocking, and shall bear the foundry identification and the AASHTO M306 mark.
−
## Casting Material {toc}
…189 unchanged lines
### This zone provides the primary structural support for flexible pipe. {note}
+### The pipe zone shall be filled with the same Class I or Class II material as the bedding, placed in lifts and worked into the haunches with shovel slicing or rod tamping for the lower haunches, and compacted in subsequent lifts up to the top of the pipe zone.
+
```datasheet
label: Pipe Zone Backfill Material
…7 unchanged lines
```
+### Heavy compaction equipment shall not operate directly over the pipe until at least 12 inches of cover has been placed and compacted in lifts.
+
+### Vibratory compaction over flexible pipe with insufficient cover produces large dynamic loads on the pipe and can crush or deflect the pipe beyond the acceptable 5 percent limit. {note}
+
+### The Contractor shall use hand-operated plate compactors or jumping jack tampers within the pipe zone, transitioning to heavier equipment only after enough cover has been placed to protect the pipe.
+
```datasheet
label: Pipe Zone Backfill Compaction
…8 unchanged lines
```
−### The pipe zone shall be filled with the same Class I or Class II material as the bedding, placed in lifts and worked into the haunches with shovel slicing or rod tamping for the lower haunches, and compacted in subsequent lifts up to the top of the pipe zone.
−
−### Heavy compaction equipment shall not operate directly over the pipe until at least 12 inches of cover has been placed and compacted in lifts.
−
−### Vibratory compaction over flexible pipe with insufficient cover produces large dynamic loads on the pipe and can crush or deflect the pipe beyond the acceptable 5 percent limit. {note}
−
−### The Contractor shall use hand-operated plate compactors or jumping jack tampers within the pipe zone, transitioning to heavier equipment only after enough cover has been placed to protect the pipe.
−
## Minimum and Maximum Cover {toc}
…318 unchanged lines
## After all testing is complete and before the system is turned over to the Owner or the AHJ, the entire storm drainage system is cleaned of debris, sediment, mortar droppings, and any construction materials. {note}
+## Cleaning shall be performed by jet-flushing, by mechanical bucketing, or by other methods suited to the pipe size and configuration.
+
```datasheet
label: Final System Cleaning Method
…7 unchanged lines
```
−## Cleaning shall be performed by jet-flushing, by mechanical bucketing, or by other methods suited to the pipe size and configuration.
−
## Sediment removed during cleaning shall be disposed of off-site or, where the project has an on-site stormwater facility, at an Owner-approved location.
…16 unchanged lines
## Where the project includes pre-treatment or water quality structures within the storm drainage system — including oil-water separators, hydrodynamic separators, gross particle separators, sand filters, or bioretention discharge structures — those structures are typically proprietary devices governed by the manufacturer's installation instructions and the civil drawings. {note}
+## The pipe and structure installation provisions of this standard apply to the pipe connections into and out of the device.
+
+## The device itself shall be installed per the manufacturer's instructions and the civil details.
+
+## Oil-water separators are required by local stormwater regulations or by the NPDES MS4 program for runoff originating in vehicular fueling, vehicle service, or industrial yard areas. {note}
+
+## Where required, the separator shall be located upstream of the storm system connection to the public infrastructure and shall be sized per the manufacturer's procedure for the contributing drainage area and the design storm.
+
+## The Contractor shall not omit a specified water-quality structure.
+
```datasheet
label: Pre-Treatment / Water Quality Structures Included
…9 unchanged lines
```
−## The pipe and structure installation provisions of this standard apply to the pipe connections into and out of the device.
−
−## The device itself shall be installed per the manufacturer's instructions and the civil details.
−
−## Oil-water separators are required by local stormwater regulations or by the NPDES MS4 program for runoff originating in vehicular fueling, vehicle service, or industrial yard areas. {note}
−
−## Where required, the separator shall be located upstream of the storm system connection to the public infrastructure and shall be sized per the manufacturer's procedure for the contributing drainage area and the design storm.
−
−## The Contractor shall not omit a specified water-quality structure.
−
## Omitting a specified water-quality structure creates a downstream permit violation and an Owner liability that survives the warranty period. {note}
…56 unchanged lines
## Pipe installed at incorrect slope, structures with leaking joints concealed by exterior backfill, castings under-rated for the load class of the location, or pipe materials substituted from the specified standard remain the Contractor's responsibility as latent defects whenever discovered. {note}